The Arizona-based world number 57 is in control of this event, putting like a dream on the Brabazon course's bumpy greens, whereas Clarke is playing from memory at a venue he dislikes.

Not that his recall is second-rate or anything like that, it's simply that the longer the tournament goes on, and the higher the pressure quotient, the harder Clarke is finding it.

With little or no preparation due to his wife's illness, and with even less expectation, he surprised himself by getting into contention in the first place. He wasn't too sure about the how and why of it all, but he was quick to point out that his notorious temper had been well under control. That was until yesterday when he had that alltoo familiar hangdog look, and when his driver took some punishment following a wayward tee shot at the 17th hole. Yet, for all the negative body language, Clarke finds himself alone in third place, three strokes adrift of Casey and one behind Michael Campbell.

The gap looked as if it was going to be much wider, however, Casey's pulled approach to the final green led to a bogey, a round of 70 and a 13under-par total of 203, while Clarke matched the leader's 70 with an impressive closing birdie for 206.

"You'd have to use the sort of words you guys aren't allowed to use to describe the way I played, " he explained afterwards.

"I didn't lay a clubface on it at any stage, I made a lot of mistakes, I ground it out and I had couple of good breaks at the end. I just about managed to get it round."

If Clarke has his mind on other things, and if he is playing down his chances of a surprise victory, the competitor in him is alive and well. But that is probably all . . . this first title of the European Tour's British and Irish swing appears to be between Casey and the New Zealander, Campbell.

Unlike Clarke, his recent break from the game was not enforced, and four weeks on an Australian beach appears to have worked wonders for the reigning US Open champion whose last round before this tournament was at the Masters.

Undeterred by a radical change in conditions which shifted from those of high summer on Friday to cool and damp yesterday, Campbell opened up with three birdies to draw level with Casey.

His cough was softened by a double bogey at the ninth, but he was rarely in trouble from that moment on to card an equal best-of-the-day 68.

"Michael is the man to beat, " revealed Casey with a hint of a smile, "he's the major champion."

Campbell then explained that when Casey was struggling badly with his game last year, he offered the Englishman some advice which apparently included some class of a side bet between the two players.

"I'm not going to tell you exactly what it's all about, " said Campbell, "but Paul's a friend of mine and I knew what he was going through, and I hope I helped a bit when we talked. The betting thing acts as an incentive between us.

"If I see his name on a leaderboard ahead of me, it makes me push that bit harder, and I presume it's the same for him."

Meanwhile, the Ryder Cup might be four months, and a run of points-rich tournaments, away, but Europe captain Ian Woosnam's decision to put the qualification race on the agenda with his recent suggestion that both Padraig Harrington and Lee Westwood needed to get off their backsides, added an edge to this event.

With the K Club in mind, the week has been mixed for Woosnam. Despite nursing a bad back, the captain comfortably made the cut playing distinctly better golf than Paul McGinley, Henrik Stenson, Colin Montgomerie and Westwood who all had the weekend off.

While there is plenty of time for McGinley, Stenson and Montgomerie . . . the Scot has now missed six cuts in his last eight starts . . . to rediscover the form that appears to have already assured them of automatic places for the September matches, Westwood remains off the pace.

As for McGinley, who was able to make the two-hour drive to Cardiff without any talk of clock-watching or chopper transfers, it goes without saying he would rather have been in contention here than spectating at the FA Cup final.

Elsewhere, Woosnam will have been heartened by the performances of Casey and Clarke and to a lesser extent, Ian Poulter, but he probably was looking for more from Harrington who after a second round 66, slipped back into the pack with a disappointing 74.

"I had a few innocuous bogeys out there, " Harrington said after his round, "and on another day you wouldn't have them. That's it in a nutshell really." Graeme McDowell, who will also be on Woosnam's radar over the summer, failed to make any inroads with a one-over par 73 to lie eight strokes off the lead, while David Higgins is in line to make his best cheque of the season after a 71 for 214.

As for Clarke, the odds are against him lasting the pace.

Casey and Campbell, playing in the last group together, will have something more than a side bet on their minds today.